New Cytotoxic Triterpenoid Saponins from the Roots of Albizia gummifera (J.F.Gmel.) C.A.Sm.

As part of our search for new bioactive saponins from Cameroonian medicinal plants, two new oleanane-type saponins, named gummiferaosides D and E (1 and 2), along with one known saponin, julibroside J8 (3), were isolated from the roots of Albizia gummifera. Their structures were established on the basis of extensive 1D- and 2D-NMR (1 H- and 13 C-NMR, DEPT, COSY, TOCSY, NOESY, HSQC, HSQC-TOCSY, and HMBC) and HR-ESI-MS studies, and by chemical evidence. The apoptotic effect of saponins 1 - 3 was evaluated on the A431 human epidermoid cancer cell. Flow cytometric analyses showed that saponins 1 - 3 induced apoptosis of human epidermoid cancer cell (A431) in a dose-dependent manner.

Pregnane Glycosides from Cynanchum marnierianum Stimulate GLP-1 Secretion in STC-1 Cells.

In the framework of the search for natural glucagon-like peptide-1 secretagogues, the bioassay-guided fractionation of the ethanolic extract from Cynanchum marnierianum led to the isolation of two new pregnane glycosides named marnieranosides A (1) and B (2). The structures were determined based on spectroscopic data and were established as 12ß,20 S-O-dibenzoyl-pregn-6-en-5α,8ß,14ß,17ß-tetraol-3-O-ß-D-oleandropyranosyl-(1 → 4)-ß-D-cymaropyranoside (1) and 12ß,20R-O-dibenzoyl-pregn-6-en-5α,8ß,14ß-triol-3-O-ß-D-oleandropyranosyl-(1 → 4)-ß-D-canaropyranosyl-(1 → 4)-ß-D-cymaropyranoside (2). They present structural analogies to pregnanes previously described in species known for their appetite suppressant and antihyperglycemic effects, such as P57 from Hoodia gordonii. Lupeol (3), a known dipeptidyl peptidase-4 inhibitor, and the insulinomimetic kaempferol-3-O-neohesperidoside (4) were also identified in C. marnierianum. In an in vitro assay on secretin tumor cell line-1 cells, compounds 1, 2, and P57 were found to stimulate the secretion of GLP-1 by 130 % (all tested at 100 µM). These results suggest that C. marnierianum could be of great interest in the treatment of type 2 diabetes, and that pregnane derivatives should be partly responsible via the stimulation of glucagon-like peptide-1 secretion.

Chemical Constituents from the Aerial Parts of Cyrtopodium paniculatum.

We report the first phytochemical study of the neotropical orchid Cyrtopodium paniculatum. Eight new compounds, including one phenanthrene 1, one 9,10-dihydro-phenanthrene 2, one hydroxybenzylphenanthrene 3, two biphenanthrenes 4-5, and three 9,10 dihydrophenanthrofurans 6-8, together with 28 known phenolic compounds, mostly stilbenoids, were isolated from the CH2Cl2 extract of its leaves and pseudobulbs. The structures of the new compounds were established on the basis of extensive spectroscopic methods.

Two New Stilbenoids from the Aerial Parts of Arundina graminifolia (Orchidaceae).

Two new phenanthrene derivatives, a phenanthrenequinone named arundiquinone (1) and a 9,10-dihydrophenanthrene named arundigramin (2) together with a known lignin dimer (3) and seven known stilbenoids (4-10) were isolated from the aerial parts of the Asian orchid Arundina graminifolia. The structures of the isolated compounds were elucidated by spectroscopic methods, including extensive 1D, 2D NMR (heteronuclear single quantum coherence (HSQC), heteronuclear multiple-bond correlation spectroscopy (HMBC), and HR-ESI-MS techniques, as well as comparison with respective literature reports. The cytoprotective activity of the isolated compounds were evaluated for their ability to reduce beta amyloid induced toxicity on undifferentiated PC12 cells. Compound 8 showed moderate cytoprotective activity at 0.5 µmol/L (71% of cell viability) while the other compounds showed no significant activity at the highest concentration tested.

Tampering with cell division by using small-molecule inhibitors of CDK-CKS protein interactions.

Cyclin-dependent kinases (CDKs) control many cellular processes and are considered important therapeutic targets. Large collections of inhibitors targeting CDK active sites have been discovered, but their use in chemical biology or drug development has been often hampered by their general lack of specificity. An alternative approach to develop more specific inhibitors is targeting protein interactions involving CDKs. CKS proteins interact with some CDKs and play important roles in cell division. We discovered two small-molecule inhibitors of CDK-CKS interactions. They bind to CDK2, do not inhibit its enzymatic activity, inhibit the proliferation of tumor cell lines, induce an increase in G1 and/or S-phase cell populations, and cause a decrease in CDK2, cyclin A, and p27(Kip1) levels. These molecules should help decipher the complex contributions of CDK-CKS complexes in the regulation of cell division, and they might present an interesting therapeutic potential.

Selective ROS-dependent p53-associated anticancer effects of the hypoxoside derivative rooperol on human teratocarcinomal cancer stem-like cells.

Cancer stem cells (CSCs) are potential targets for innovative anticancer therapies that involve natural products with potential chemopreventive effects. We therefore analyzed the antineoplastic activity of rooperol, the aglycone of the plant-derived compound hypoxoside, on a model of Oct4-expressing cancer stem-like cell, i.e. the human embryonal carcinoma (EC) cell NT2/D1. Rooperol selectively inhibited the proliferation of NT2/D1 cells in a concentration-dependent manner and had no effect on either normal embryonic fibroblasts which are more restrictive pluripotent stem cells or on NCCIT p53-mutant EC cells. Accordingly, rooperol only eliminates colon carcinoma cells expressing p53. Rooperol treatment triggered cell death on NT2/D1 cells through the alteration of mitochondrial membrane potential and production of reactive oxygen species (ROS). Rooperol-induced apoptosis was associated with activation of p53 and concentration-dependent changes of the expression levels of both caspase 3 and poly ADP ribose polymerase type 1 cleaved subunits. These modifications were accompanied by a downregulation of Oct4 and its two partners involved in the maintenance of cell pluripotency and self-renewal, Nanog and Sox2.Treatment with intracellular membrane permeant O2 (-) scavengers prevented rooperol-induced apoptosis and upregulation of the expression of p53 and active caspase-3. Our findings indicate that rooperol mediates its growth inhibitory effects on CSCs via a mitochondrial redox-sensitive mechanism. We propose that abrogating the expression of the stemness regulators is a prerequisite for rooperol to fully exert its pro-apoptotic properties on wild-type p53-bearing CSCs.

Purification of vandaterosides from Vanda teres (Orchidaceae) by stepwise gradient centrifugal partition chromatography.

Vandaterosides are polar glucosyloxybenzyl eucomate derivatives found in Vanda teres (Orchidaceae), which display biological activities that slow the skin ageing process. In order to obtain larger quantities to allow us to go further in the bioassays, the hydroalcoholic extract of aerial parts (leaves and stems) of V. teres were fractionated by centrifugal partition chromatography, combining isocratic, gradient, and dual elution modes. The first fractionation was performed on the extract maintained in the stationary phase as water saturated in butanol, while increasing the polarity of the mobile phase by changing the proportions of ethyl acetate/1-butanol/water, in order to obtain two enriched fractions. Vandateroside I was then purified by isocratic mode with ethyl acetate/ethanol/water (46:14:40), while vandateroside II was obtained by combining isocratic elution with ethyl acetate/isopropanol/water (30:20:50) followed by a multiple dual mode with ethyl acetate/ethanol/water (46:14:40). In this manner, hundreds of milligrams of vandateroside I and II were recovered from 10 g of V. teres extract.

Identification of phenanthrene derivatives in Aerides rosea (Orchidaceae) using the combined systems HPLC-ESI-HRMS/MS and HPLC-DAD-MS-SPE-UV-NMR.

INTRODUCTION: In our continued efforts to contribute to the general knowledge on the chemical diversity of orchids, we have decided to focus our investigations on the Aeridinae subtribe. Following our previous phytochemical study of Vanda coerulea, which has led to the identification of phenanthrene derivatives, a closely related species, Aerides rosea Lodd. ex Lindl. & Paxton, was chosen for investigation. OBJECTIVE: To identify new secondary metabolites, and to avoid isolation of those already known, by means of the combined systems HPLC-DAD(diode-array detector) with high-resolution tandem mass spectrometry (HRMS/MS) and HPLC-DAD-MS-SPE(solid-phase extraction)-UV-NMR. METHODS: A dereplication strategy was developed using a HPLC-DAD-HRMS/MS targeted method and applied to fractions from A. rosea stem extract. Characterisation of unknown minor compounds was then performed using the combined HPLC-DAD-MS-SPE-UV-NMR system. RESULTS: The dereplication method allowed the characterisation of four compounds (gigantol, imbricatin, methoxycoelonin and coelonin), previously isolated from Vanda coerulea stem extract. The analyses of two fractions permitted the identification of five additional minor constituents including one phenanthropyran, two phenanthrene and two dihydrophenanthrene derivatives. The full set of NMR data of each compound was obtained from microgram quantities. CONCLUSION: Nine secondary metabolites were characterised in A. rosea stems, utilising HPLC systems combined with high-resolution analytical systems. Two of them are newly described phenanthrene derivatives: aerosanthrene (5-methoxyphenanthrene-2,3,7-triol) and aerosin (3-methoxy-9,10-dihydro-2,5,7-phenanthrenetriol).

[Nursing care and essential oils in geriatrics]. / Soins infirmiers et huiles essentielles en gériatrie.

Aromatherapy is a valuable complementary therapeutic tool which is increasingly being used in hospitals. Essential oils help to improve patients' quality of life. They can be used for well-being purposes as well in specific nursing procedures. Some services offer aromatherapy through diffusion, inhalation, massages or aromatic baths. The benefits for healthcare teams as well as for patients are undeniable. There is also a significant reduction in the consumption of certain drugs.

[Augustin Delondre and Friedrich AuguIst Flückiger : an unpublished correspondence 1868-1869]. / Augustin Delondre et Friedrich August Flückiger : une correspondance inédite 1868-1869.

This article describes an unpublished correspondence between Augustin-Ambroise Delondre (1823- 1879), son of the famous pharmacist Augustin - Pierre Delondre and Friedrich August Flückiger, Swiss pharmacist (1828-1894), professor between 1873 to 1892 of the Chair in pharmacy at the university of Strasbourg and considered as the father of pharmacognosy. This set of 9 unique hand- written letters (1868 and 1869) allows to have an clearer idea of their scientific and human relations.

Eleganolone, a diterpene from the French marine alga Bifurcaria bifurcata inhibits growth of the human pathogens Trypanosoma brucei and Plasmodium falciparum.

Organic extracts of 20 species of French seaweed have been screened against Trypanosoma brucei rhodesiense trypomastigotes, the parasite responsible for sleeping sickness. These extracts have previously shown potent antiprotozoal activities in vitro against Plasmodium falciparum and Leishmania donovani. The selectivity of the extracts was also evaluated by testing cytotoxicity on a mammalian L6 cell line. The ethyl acetate extract of the brown seaweed, Bifurcaria bifurcata, showed strong trypanocidal activity with a mild selectivity index (IC(50) = 0.53 µg/mL; selectivity index (SI) = 11.6). Bio-guided fractionation led to the isolation of eleganolone, the main diterpenoid isolated from this species. Eleganolone contributes only mildly to the trypanocidal activity of the ethyl acetate extract (IC(50) = 45.0 µM, SI = 4.0). However, a selective activity against P. falciparum erythrocytic stages in vitro has been highlighted (IC(50) = 7.9 µM, SI = 21.6).

Arundinosides I-IX and graminifolosides A-B: 2R-benzylmalate and 2R-isobutylmalates derivatives from Arundina graminifolia (D.Don) Hochr. with antioxidant, cytocompatibility and cytoprotective properties.

Phytochemical investigation of the underground parts of Arundina graminifolia D.Don Hochr was conducted leading to the isolation of nine new glucosyloxybenzyl 2R-benzylmalate and two new glucosyloxybenzyl 2R-isobutylmalate derivatives. The compounds were purified using chromatographic techniques and their structures were deduced based on spectroscopic techniques including nuclear magnetic resonance and high-resolution mass spectrometry as well as comparing with previous literature. The antioxidant activities of the isolated compounds were also evaluated. The compounds showed potent antioxidant activities in the ABTS radical scavenging, DPPH radical scavenging and FRAP activities. Furthermore, the isolated compounds were observed to exert minimal cytotoxic effects against RAW 264.7 cell, suggesting biocompatibility as well as cytoprotective effects against hydrogen peroxide induced cell toxicity.

(10E,12E,14E)-9,16-Dioxoocta-deca-10,12,14-trienoic acid.

The title octa-deca-trienoic acid derivative, C(18)H(26)O(4), was isolated from Silene maritima With. (Caryophyllaceae), the first time this natural compound has been found in the Caryophyllales order. This fatty acid has an 18-carbon backbone with three double bonds on trans (E) conformation and two carbonyl. In the crystal, molecules are linked via pairs of O-H⋯O hydrogen bonds, forming inversion dimers.

In vitro antileishmanial, antiplasmodial and cytotoxic activities of a new ventiloquinone and five known triterpenes from Parinari excelsa.

CONTEXT: Parinari excelsa Sabine (Chrysobalanaceae) is an indigenous tree from West and Eastern Africa. This tree is used in Ivory Coast as an antimalaria remedy. OBJECTIVE: The in vitro antiplasmodial and antileishmanial activities of the stem bark, the leaf and the major compounds from the stem bark were investigated. MATERIALS AND METHODS: The leaves and stem bark from P. excelsa were separately collected, air-dried and powdered. Two extracts (methylene chloride and methanol) were realized for both powders. Every extract was tested for its antiplasmodial and antileishmanial activities. Only the stem bark crude extracts were fractionated by column chromatography and their major components were analyzed by NMR, HRESIMS and IR methods. The compounds were tested for their antiplasmodial and antileishmanial activities. RESULTS: The comparison of the IC(50) values of the crude extracts were in this order: 3.41 (IC(50) of PeBMc) <4.10 (IC(50) of PeBMc) <4.42 (IC(50) of PeLMe) against P. falciparum and 5.19 (IC(50) of PeBMc) <12.32 (IC(50) of PeBMe) <19.33 (IC(50) of PeLMc) <32.37 (IC(50) of PeLMe) against L. donovani. The stem bark crude extracts were the most active against both parasites. Their fractionation leaded to a new ventiloquinone, five triterpenes and one chlorogenic acid. All these compounds were isolated for the first time from P. excelsa. High activities were observed with (3ß)-3-hydroxyolean-12-en-28-oic acid (IC(50) = 8.2 µM) and 3ß-hydroxyolean-5,12-dien-28-oic acid (IC(50) = 7.7 µM) against L. donovani. With the antiplasmodial activity, the best activity was observed with 16ß-hydroxylupane-1,20(29)-dien-3-one (IC(50) = 28.3 µM). DISCUSSION AND CONCLUSION: These findings demonstrated that the constituents of P. excelsa stem bark have in vitro antiplasmodial and antileishmanial activities.

Glucosyloxybenzyl eucomate derivatives from Vanda teres stimulate HaCaT cytochrome c oxidase.

Eucomic acid [(2R)-2-(p-hydroxybenzyl)malic acid)] (1) and three new glucopyranosyloxybenzyl eucomate derivatives, vandaterosides I (2), II (3), and III (4), were isolated and identified from the stems of Vanda teres. Their cellular antiaging properties were evaluated in a human immortalized keratinocyte cell line (HaCaT) by monitoring their effect on cytochrome c oxidase activity, implicated in mitochondrial respiratory function and cellular energy production. Eucomic acid (1) and vandateroside II (3) increased cytochrome c oxidase activity and/or expression, without enhancing cellular mitochondrial content. These two V. teres biomarkers apparently contributed to stimulate respiratory functions in keratinocytes. Since aging and its pathologies may be ascribed to a decline in mitochondrial functions, these biomarkers have the potential to become new natural ingredients for antiaging preparations to remedy age-related disorders such as skin aging.

Early modulation of gene expression used as a biomarker for chemoprevention in a preclinical model of colon carcinogenesis.

By using the rat azoxymethane (AOM)-induced colon carcinogenesis model, which mirrors many clinical features of human colorectal cancer, we examined whether genetic changes occurring early in colonic mucosa are predictive of treatment efficacy. In the present study the administration of the chemopreventive agent lupulone over the course of 7 weeks postinitiation reduced the number of preneoplastic lesions in the colonic mucosa by 50%. At the molecular level we observed the downregulation of genes involved in the inflammatory response, including IL-1ß and TNF-α, and of matrix metalloproteinase-7 gene and protein expression. We also observed a substantial upregulation of components of the innate immune system, α-defensin-5 and lipocalin 2. Lupulone induced the expression of apoptosis-related genes and caused a reversal of the B-cell lymphoma/leukemia 2 (Bcl-2; antiapoptotic) to Bcl-2 associated X protein (Bax; proapoptotic) transcript and protein ratios (Bcl-2/Bax > 1 in AOM controls and Bcl-2/Bax < 1 in lupulone-treated AOM rats). Here, we identify several target genes that could be considered early biomarkers of colon carcinogenesis and indicative of drug efficacy.

The EGCg-induced redox-sensitive activation of endothelial nitric oxide synthase and relaxation are critically dependent on hydroxyl moieties.

Several rich sources of polyphenols stimulate the endothelial formation of nitric oxide (NO), a potent vasoprotecting factor, via the redox-sensitive activation of the PI3-kinase/Akt pathway leading to the phosphorylation of endothelial NO synthase (eNOS). The present study examined the molecular mechanism underlying the stimulatory effect of epicatechins on eNOS. NO-mediated relaxation was assessed using porcine coronary artery rings in the presence of indomethacin, and charybdotoxin plus apamin, inhibitors of cyclooxygenases and EDHF-mediated responses, respectively. The phosphorylation level of Akt and eNOS was assessed in cultured coronary artery endothelial cells by Western blot, and ROS formation using dihydroethidine. (-)-Epigallocatechin-3-O-gallate (EGCg) caused endothelium-dependent relaxations in coronary artery rings and the phosphorylation of Akt and eNOS in endothelial cells. These responses were inhibited by membrane-permeant analogues of superoxide dismutase and catalase, whereas native superoxide dismutase, catalase and inhibitors of major enzymatic sources of reactive oxygen species including NADPH oxidase, xanthine oxidase, cytochrome P450 and the mitochondrial respiration chain were without effect. The EGCg derivative with all hydroxyl functions methylated induced neither relaxations nor the intracellular formation of ROS, whereas both responses were observed when the hydroxyl functions on the gallate moiety were present. In conclusion, EGCg causes endothelium-dependent NO-mediated relaxations of coronary artery rings through the Akt-dependent activation of eNOS in endothelial cells. This response is initiated by the intracellular formation of superoxide anions and hydrogen peroxide, and is critically dependent on the gallate moiety and on the presence of hydroxyl functions possibly through intracellular auto-oxidation.

Identification by high-throughput screening of inhibitors of Schistosoma mansoni NAD(+) catabolizing enzyme.

Schistosomiasis is a major tropical parasitic disease. For its treatment, praziquantel remains the only effective drug available and the dependence on this sole chemotherapy emphasizes the urgent need for new drugs to control this neglected disease. In this context, the newly characterized Schistosoma mansoni NAD(+) catabolizing enzyme (SmNACE) represents a potentially attractive drug target. This potent NAD(+)glycohydrolase, which is localized to the outer surface (tegument) of the adult parasite, is presumably involved in the parasite survival by manipulating the host's immune regulatory pathways. In an effort to identify SmNACE inhibitors, we have developed a sensitive and robust fluorometric high-throughput screening assay. The implementation of this assay to the screening of a highly diverse academic chemical library of 14,300 molecules yielded, after secondary assays and generation of dose-response curves, the identification of two natural product inhibitors, cyanidin and delphinidin. These confirmed hits inhibit SmNACE with IC(50) values in the low micromolar range. To rationalize the structure-activity relationship, several related flavonoids were tested, thereby leading to the identification of 15 additional natural product inhibitors. A selection of representative flavonoid inhibitors indicated that although they also inhibit the homologous human CD38, a selectivity in favor of SmNACE could be reached. Docking studies indicated that these inhibitors mimic the binding mode of the enzyme substrate NAD(+) and suggested the pharmacophoric features required for SmNACE active site recognition.

Structure elucidation of new acacic acid-type saponins from Albizia coriaria.

Three new acacic acid derivatives, named coriariosides C, D, and E (1-3) were isolated from the roots of Albizia coriaria. Their structures were elucidated on the basis of extensive 1D- and 2D-NMR studies and mass spectrometry as 3-O-[ß-D-xylopyranosyl-(1 → 2)-ß-D-fucopyranosyl-(1 → 6)-2-(acetamido)-2-deoxy-ß-D-glucopyranosyl]-21-O-{(2E,6S)-6-O-{4-O-[(2E,6S)-2,6-dimethyl- 6-O-(ß-D-quinovopyranosyl)octa-2,7-dienoyl]-4-O-[(2E,6S)-2,6-dimethyl-6-O-(ß-D-quinovopyranosyl)octa-2,7-dienoyl]-ß-D-quinovopyranosyl}-2,6-dimethylocta-2,7-dienoyl}acacic acid 28-O-ß-D-xylopyranosyl-(1 → 4)-α-L-rhamnopyranosyl-(1 → 2)-ß-D-glucopyranosyl ester (1), 3-O-{ß-D-fucopyranosyl-(1 → 6)-[ß-D-glucopyranosyl-(1 → 2)]-ß-D-glucopyranosyl}-21-O-{(2E,6S)-6-O-{4-O-[(2E,6S)-2,6-dimethyl-6-O-(ß-D-quinovopyranosyl)octa-2,7-dienoyl]-4-O-[(2E,6S)-2,6-dimethyl-6-O-(ß-D-quinovopyranosyl)octa-2,7-dienoyl]-ß-D-quinovopyranosyl}-2,6-dimethylocta-2,7-dienoyl}acacic acid 28-O-α-L-rhamno pyranosyl-(1 → 2)-ß-D-glucopyranosyl ester (2), and 3-O-[ß-D-fucopyranosyl-(1 → 6)-ß-D-glucopyranosyl]-21-O-{(2E,6S)-6-O-{4-O-[(2E,6S)-2,6-dimethyl-6-O-(ß-D-quinovopyranosyl)octa-2,7-dienoyl)-ß-D-quinovopyranosyl]octa-2,7-dienoyl}acacic acid 28-O-ß-D-glucopyranosyl ester (3).